The canning trend is also being fuelled by newcomers to the practice, such as James Padwick and Tracie Donald of Toronto. The couple grows a variety of fruits and veggies, including tomatoes, peppers and cucumbers, on a rooftop garden in the city's west end.

According to Trail, jarring up high-acid preserves such as tomatoes, pickles and chutneys is a good way for novice canners to get their feet wet before attempting trickier projects such as jams and jellies. It also diminishes the risk of botulism and other bacterial nastiness that thrives in low-acid environments. Before preserving whole tomatoes, Trail makes two criss-cross slits on the bottom of each and cuts off any hard cores or bad parts.

Once the tomatoes have been peeled, Trail drops a tablespoon of lemon juice into each sterilized jar and pushes the tomatoes in with her fingers or a wooden spoon, using a funnel to prevent spillage and leaving half an inch of headspace from the top.

After the jars have been processed in a boiling water bath, Trail removes them from the pot, sets them aside to cool and waits for the popping sound that indicates a successful seal. The result: an array of delicious tomato preserves to see her through the winter.